


We Are Sinners (Father, Forgive Us)

by ArtsyDeath



Category: Harry Potter - J. K. Rowling
Genre: Age Difference, Alpha Sirius Black, Alternate Universe - Gender Changes, Dubious Consent, Dubious Morality, F/M, Female Harry Potter, First Time, Knotting, Naked Female Clothed Male, Non-Traditional Alpha/Beta/Omega Dynamics, Not Safe Sane and Consensual, Older Man/Younger Woman, Omega Harry Potter, Oral Sex, Porn With Plot, Power Dynamics, Rough Sex, Size Difference, Size Kink, Somnophilia, Vaginal Sex
Language: English
Status: Completed
Published: 2019-03-13
Updated: 2019-03-13
Packaged: 2019-11-16 16:24:27
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,831
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18097898
Author URL: https://archiveofourown.org/users/ArtsyDeath/pseuds/ArtsyDeath
Summary: Harry loves Sirius - this she knows to be as true as the sky is blue and the grass beneath her feet green. She shouldn't want him but she does, a secret carefully hidden for but a moment of weakness.But Sirius has secrets too and Harry is about to learn just how much obsession can mean, want stretching from one generation to the next.-Or: Harry wants Sirius but Sirius looks at her and he sees two people where there should be one (wants them both and takes what he can).





	We Are Sinners (Father, Forgive Us)

“Harry? Hey - what are you doing in here? I’ve been looking all over for you.” 

Harry squeezes her eyes shut, hating her body, hating the want that curls heady inside of her at the sound of his voice, the smooth glide, the scent of _alphaalphalpha_ that made her want to tilt her head up, bare her neck and succumb to his touch as he stepped closer, inhaling the wretched want of her heat with widening eyes.

It’s just the two of them in the house – the Weasleys away for an outing, Hermione along with them. A celebratory dinner for their graduation from Hogwarts and Harry was supposed to spend it with Sirius.

She’d been looking forward to it the whole week, a chance to spend it with her godfather, undisturbed by anyone else.

And instead-

“Oh, Prongslet…” The sound of the nickname shouldn’t be making her walls squeeze down on nothing as he gently closes the door behind him and she peers up at him miserably, wrapped up in one of his cloaks and curled up in the middle of his bed in weak excuse of a nest.

“Hey,” he says gently, smiling. “Is it okay if I…?” He gestures to the end of the bed and she nods, drawing her knees to her chest beneath the cloak and tucking her chin on top of them.

He approaches her cautiously, his steps slow and steady, but it’s his room, his scent, his cloak, his bed- Harry is practically marinating in the comfort of his familiarity and it takes everything she has not to stretch out and push into his lap, to beg for him to touch her, to sooth the ache of her heat as he seats himself gingerly.

Despite the scent of her arousal he manages to look perfectly unruffled, more worried than anything, and she swallows – ashamed by her want, embarrassed by her body’s reaction to him as it squeezes down with a rush of slick as she inhales the mix of wood and smoke that clings to him.

“Is this your first one…?” he ventures carefully and she shakes her head. “That’s good,” he breathes out. “Is there anything I can fetch for you? More blankets? Water?”

The thought of him leaving makes her reach out – hand grasping at his shirt and curling around the fabric firmly as her mouth dips down and she shakes her head.

Sirius blinks at her grip, looking surprised.

“Stay,” she gets out, flushing at the sound of her voice, the want that makes her breathing go ragged and she yanks her hand back into the darkness of her cloak, digging her fingers into her ribs and looking away.

There’s a rustle, a hand reaching out to settle on her shoulder, sending a shiver through her as he draws her towards him, giving her every chance to pull away as he tucks her up against his side and she bites down on her lip but allows herself to tilt her head to lean it against his shoulder.

“It’s nothing to be embarrassed about, Prongslet. Your father was an omega, I’ve walked in on him plenty of times during the years. It was unavoidable with us living so closer – sharing a room during summer, the same dormitory during Hogwarts.” There’s nothing but fond nostalgia in his voice and Harry breathes his scent, focusing on the low murmur as he speaks, trying to ignore instincts and wants, absently rubbing her thighs together with a small grimace at the feel of stickiness.

It doesn’t take long before she’s lulled into sleep – exhausted but safe as her eyes lid and she nods off.

-

Harry wakes up with a squirm, pushing back against the delicious feel of something straining against her rump, arms wrapped around her, on her side with warm air ghosting over her ear.

Her breathing hitches when it pushes up against her with a low groan, her heat flaring thickly with want as she spreads her legs instinctively, feeling the bulge of an erection through rough jeans – eyes melting into omega golden as they droop with pleasure.

She’s surrounded by smoke and wood, pulled up against an impossibly warm body, biting down on her lip as she struggles to make sense of the situation and body behind her as it humps against her, arms squished flat against her sides as the man pulls her down and pushes up with a murmur.

She stills at the sound of the voice, eyes growing wide.

“Siri-“

Harry jerks, a strange feeling worming through her when one of his hands dips down, past the hem of her jeans with a curl of fingers that disappear into her as her mouth opens wide, hissing out in shock as she squeezes down hard on him, her body instinctively trying to pull him deeper as he pushes his straining cock against her rump with a groan as her mouth goes dry.

 _You shouldn’t be allowing him to do this to you,_ her mind reminds her as she feels the pads of his fingers dragging against her walls which pulses and squeezes wetly around him, the wrongness of the situation making her heart ache even as deep and delicious want made her omega purr. _He’s asleep, you shouldn’t-_

She spreads her legs as best as she can, taking him deeper, straining as he drags her back against him, humping against her as he fucks into her with long rough fingers and she squeezes her eyes shut, cheeks coloured red, depraved to be getting off on her godfather’s fingers but unable to deny the building of her orgasm as she squirms in his grip.

She comes hard, scent flaring, jerking and squeezing down hard with an embarrassingly wet noise and he groans against her ear, teeth scraping against her skin as he thrusts up hard with his hips.

His fingers slip out of her, palm flattening against the brush of pubes, and Harry pushes against her jeans as best as she can in his grip, using her feet to get them the last bit down and kicking them off the bed as she feels the rough push of the bulge in the jeans against the thin fabric of her underwear and bare thighs.

Harry bites down on the inside of her cheek as she wiggles one arm free, her breathing deepening as she pushes it back and down between them until she finds the thick bulge of his erection, quivering as he pushes into her hand as she squeezes down, eyes shutting at the feeling.

It takes a bit of manoeuvring but she gets the button undone, tugging the fly down, his muscles straining as she pushes the fabric of his boxers down until it slips over his cock, freeing his erection with a wet smack up against her as he jerks.

Harry shifts her hips, just enough to get the cock between her thighs with the next thrust, squeezing down and trapping it there as he fucks against her with a groan.

 _No further,_ she promises herself at the feel of him as he humps between her thighs, straining her around his thickness, watching the head poking up and out below her panties with every thrust forward and she loses herself to the feeling – neck bending, jerking as he curves up and against her clit, the rough push of his jeans against her rump.

The heat makes her warm and sticky with sweat – mashes down inhibitions in search of pleasure, eyes lidding as she breathes the musk of _her_ alpha.

She is unprepared for the sudden rough shift, the snag of the head pushing up against her entrance, hindered only by the fabric of her panties as he strains against it and her eyes widening at the feeling but knowing that – it was too far, shifting her hips to get him back between her thighs with a push of her knee against the bed.

But Sirius had other ideas – his hand, still flattened against her curls, twisting and dragging the panties aside with a snap as the thin fabric broke and Harry pushed down hard with her feet in sudden panic only to have his arms tighten painfully around her, pulling her down as he thrusts up.

She has no time to prepare herself – mouth opening as the large head breaches her roughly, forcing her entrance to open wide and swallow him inside as she jerks, inch after inch disappearing into her until his hips hoists up against her rump, bottoming out with a rough push against her womb, spreading her too wide and stealing her virginity as she digs her nails into his wrists, grasping and holding on desperately as he immediately pulls back and pushes into her again without consideration for anything but his own pleasure.

 _My godfather is fucking me,_ her mind recognises through the shock and pain and mounting pleasure at the drag of his cock, the push, the feeling of being spread open and filled new and strange and everything her instincts had begged her for since going into heat that morning.

The sound of his hips smacking against her, thrusts short and hard, everything about it filthy and depraved, and she shouldn’t want it but she _does_ , biting down hard enough on the inside of her cheek to draw blood, afraid of waking him up, of facing the consequences of using his body for her own pleasure as she spreads her legs to take him impossibly deeper, pushing into the feeling as best she can as her body jolts with each rough push.

 _He’ll hate me,_ Harry thinks as pleasure builds, orgasm inevitable, the knowledge of just who was filling her up making her squeeze down around him as she jerks under his rough pursuit of pleasure, egged by her pheromones.

_He’ll hate me, he’ll hate me, he’ll hate me-_

She can feel the swell of his knot at the base and she knows – she knows that she can’t allow him to push it into her, that the thirty minutes of waiting for it to go down would be _bad_ and she’s not taking any potions-

She gets a hand down between them, hanging on for dear life as he hilts himself into her over and over again, knot pushing insistently against her fingers as he struggles to get it into her, thrusting roughly and forcefully, guided by instincts to _claim_.

She feels him stiffening and twists away, cock slipping out of her, caught in the grip of her palm as cum splattered against her rump with a stuttered jerk to chase the feeling with another wad.

Harry can feel her heartbeat slowly calming inside her chest as he relaxes against her back, satisfied as her pheromones settles, his cock limp in her hand. 

_I should never have allowed this to happen._

She shifts her hips, wiggling out of his arms with embarrassment as she turns to peer down at the white against her skin.

She tucks him back with trembling fingers and buttons his jeans, magic washing away the heady mix of their coupling as she escapes to the bathroom to shower.

-

Harry spends most of the weekend inside Sirius room – playing games, drinking lots of water and getting prodded by her godfather as she watches him for any sign of strangeness, any hint of him suspecting her of foul-play.

But there is nothing.

Sirius is the same as always and Harry dares to smile back at him even as something squeezes inside her chest.

-

“Are you sure about this?” Hermione asks sceptically, looking at them both as Harry shoulders her backpack up and Molly fusses over Sirius who looks long-suffering but reluctantly amused by the armful of food already forced upon him. “They’ve been warning about a storm on the radio.”

“We’ll be fine,” Harry reassures her. “You know how magical tents are – we’ll basically be sleeping in a portable cabin.”

“You keep saying that but last time you and Sirius were on a trip you traipsed right into a nest of murder slugs,” Ron points out, biting down one of the sweat breads plucked from Sirius’ arms. “You’re a magnet for trouble, mate. You just got to accept it.”

Harry sticks her tongue out and Sirius laughs as he slings an arm around her shoulder. “We’ll be fine, don’t fret so much,” he tells her two best friends before looking down at her with steel grey eyes. “Ready to go?” he asks.

She waves goodbye to her friends as Sirius seals the food away carefully before drawing a short rope from the pocket of his leather jacket and holding it out and she grasps it firmly.

“Let the adventure-“ he begins.

“-and mischief-“ she continues.

“Begin!” they chorus with matching grins.

_“Portus!”_

-

The place Sirius had picked out for them turned out to be by a small glittering lake and Harry looks around in awe, breathing in the scent of the forest as she spins in place, enjoying the brush of air on her face as Sirius pokes their tents in place, spreading out a large blanket to drop their bags on.

“Where in the world did you find this,” Harry asks, stepping out of her shoes and poking them up beside her tent.

“Believe it or not but your father and his parents actually used to visit here during summers,” Sirius says with a stretch and crack of his back. “They brought me with them after I ran away from home at sixteen – practically made me an official brother to James, would have if my parents wouldn’t have made a _thing_ of it.” There’s an old bitterness there but he also looks fond, nostalgic even as he stares out over the clearing.

Harry tries to imagine it – Sirius just a year younger than what she was now, seated side-by-side with James Potter and his parents, _her_ grandparents.

It was strange to imagine – the most Harry remembered of her parents were her mother’s screams, imprinted after nearly a year of being hounded by dementors in her third year, and her father's ghost at the graveyard.

But to Sirius they had been people that he loved and lost.

Even now it was strange to imagine they’d both survived the war – a miracle, Harry thought personally, staring at the back of her godfather.

-

It turns out that, _maybe_ , Hermione had a point about the storm warning.

“There’s still one left,” Sirius says a bit doubtfully, watching her tent swerving in the air far away in the distance, his kept in place with some fast-acting magic from her side, and Harry wipes wet hair away from her face with a little nervous twist in her belly as she eyes the singular tent.

She drags her hair into tail and wrenches the rain out of it just outside the tent flaps before closing it up and nearly gets smacked by the towel Sirius throws at her, wet from where he’d roughly wiped down his hair and chest, already half-way out of his drenched clothes as she flushed red at the sight of his bare upper body.

“I think I have an extra shirt here somewhere…” he murmurs, digging through his bag and soon presenting one triumphantly and after a brief moment of hesitation hands over a pair of boxers as well.

Harry turns her back to him, worming out of her clothes, stripping bare before dragging the boxers up her hips, shirt pooling nearly all the way to her knees.

There’s only one bed, Harry realises, hanging her clothes up beside Sirius’ and padding over to where he’d pushed up against the wall, legs already beneath the covers, dressed in sweats and a t-shirt, patting the place beside him

“It’s a good thing we had an early dinner,” Harry points out with a little sigh as she crawls up and settles down beside him and he adjusts the covers over her as well, shoulders pushing tight together in the small surface.

“We still have some of Molly’s food for the morning,” Sirius murmurs and she’s painfully aware of his warmth, the smell of smoke and wood as she inhales. “And – I have just the thing for tonight!”

He bends down and over her, grasping beneath the bed to pull back triumphantly with a nearly full bottle of fire whisky and a pack of cards.

“Molly is going to kill you,” Harry says with a grin, grasping for the bottle and twisting the cork off as he watches her with a curious sort of look in his eyes, strangely intense as she takes a swig of the stinging liquor before trading it for the cards which she shuffles expertly before dealing them out in the first of many games.

-

Harry loses more than she wins, relaxed and comfortable with alcohol running through her veins, making her sleepy.

She makes a half-hearted protest when Sirius drags the bottle out of her hands, tongue heavy, nearly asleep as he carefully draws her against his chest, tucking them down together as she snuggles up against him with a sigh of content.

-

Harry wakes to a strange feeling, brow furrowing, trying to twist away from it with a weak brush of her hand only to have it pinned down beside her, wet and hot warmth sucking hard on her nipple as something hard and straining grinds down against her with unfamiliar roughness.

“- can’t stop thinking about you,” Sirius growls out, grasping at her hip, hitching her up against him as he flattens his tongue over her nipple. “Picturing you like this – Merlin, you’re even more beautiful than I could ever have imagined,” he says, voice ragged with want, his palms broad and rough where they slide over her skin, rubbing over her flat belly as her mind struggled to make sense of the situation through cotton thickness.

She finds her hips grasped, turned around onto her knees, a hand digging into her hair as she’s pushes down, something round pushing up against her lips, urging her to open up with a confused noise as it presses into her, forcing her down until it was curving down her throat and her jaw was straining uncomfortably around the thick member.

Reason works its way back to her as she becomes aware of the cock in her mouth, the way he guides her down, throat swallowing around him, and she realises – Sirius, he must have assumed the alcohol would knock her out for a good while yet but her magic had always burned through it quickly, a side-effect of the paranoid bit of the Dark Lord’s soul inside of her.

Anyone else would have been blackout drunk – their memories fuzzy and messy and unable to recall anything in the morning.

But Harry feels the push of her godfather’s cock, the pre cum on the tip of it, the musky scent of _alphaalphalpha_ as her jaw strains, his fingers pressing and opening her up wider as he hilts himself into her mouth, nose burying into the prickly pubes, balls pushing against her chin as he grinds himself into her throat – stealing air as she gags and he murmurs apologies and praise as he pulls her up and pushes her back down.

 _I shouldn’t allow him to do this_ , Harry thinks foggily, pressing her tongue up flat against the glide of his erection as he pulls and pushes into her, hair bunched up in a firm hold to guide her. _This is wrong._

 **More wrong than using his body to get yourself off all those months ago?** Her mind wonders as he guides the tip against her cheek, rubbing and smearing his scent into her as he works her limp body for his own pleasure.

He hilts himself into her, pushing her down into his lap to hold her there as he fills up her throat – sticky white cum working down and into her stomach as her throat swallows automatically around him, shocked as he slowly drags himself out of her with a little jerk and splash of cum against her tongue.

It’s surprisingly salty – bitter and not-good but it takes everything she has not to groan with want as she remains limp in his lap where he’d put her as a hand pats over her hair, her nose pushed up against his now limp erection.

“You look so much like him,” Sirius breathes, voice ragged. “Everything but your eyes – you have Lily’s eyes.” His thumb brushes over the curve of her lip and something inside of her aches at the loss that echoes hollowly in his voice.

She realises that he’d worked her out of her t-shirt, leaving her in nothing but a pair of his old boxers as his palm strokes down and over the skin of her back, touching the old lines from violence in her home with a tremble in his fingers.

Harry thinks that – _that’s it_ , that it’s done, but Sirius has other plans, shifting and abruptly hoisting her up against him, pulling the boxers down and off, gripping and tugging at her legs to guide them down on either side of his lap, her chin coming up to rest on his shoulder, spread obscenely over his cock.

Sirius is still wearing both boxers and sweats, pushed down just enough to get his erection out, and his shirt smells of smoke and wood where she hangs limp against him, one arm wrapped around her to keep her in place against him as his fingers brushes up against her folds, touching her with rough fingers, dipping into her to scoop out the slick there before palming himself with it, stroking himself with a mix of her saliva and want.

“I’m just going to put the tip in,” he whispers hotly against her ear, a tremble of want and desperation as she opens her eyes wide, out of his sight as the head rubs up against her, even broader and thicker than she remembered as he strains desperately against her entrance, cursing as he couldn’t quite work it into her without risking damage-

Because Harry’s body wasn’t slick with swollen want as she’d been then, heat eating reason, guiding her to accept something that should have been impossible, the cock nearly grotesque in size compared to her small and skinny body.

She jerks a bit when he pushes two fingers into her and then a third far too quickly, opening her up impatiently as he pants into her ear, groaning at her slickness, the tightness, mouth working against her skin, sucking hard – sure to bruise her skin, her nipples brushing up against his shirt with every push up into her.

The feel of her godfather inside of her brings a rush of slick want that drips down his fingers as he spreads them inside of her to a filthy groan as he reluctantly pulls out, wet fingers settling on her back as he grasps himself with the other hand, guiding the head up against her entrance and pushing up against it.

Harry forces herself not to tense, biting down as she slowly opens up around the head.

“That’s it,” Sirius gasps into her ear. “That’s it – just like that Harry, such a good girl, look at you-“

She swallows him painfully up into her and his breath turns ragged at the feel of her wetness and warmth as she struggles not to squirm at the strangeness of the feeling, at having her godfather inside of her body, the depravity of it, the knowledge that he thought she was asleep, that he thought she would never know-

“Just – maybe just once…” Sirius pushes down on her hip and Harry nearly forgets how to breathe as she was forced to swallow inch after inch into her, struggling against the feeling of being stuffed far past her limits, a tremble running through her as he never seemed to end, her walls straining painfully around his thickness until her crotch finally pushed up flat against his, the fabric of his sweats brushing against her rump.

He keeps her there for a long moment, something like a sigh leaving him as he hugs her limp body against him, mouth sucking and worrying the skin on her neck as she stares into the darkness of the tent.

“James – he was always so loud,” Sirius murmurs against her ear and the implication makes her eyes widen as he drags her up and off his cock with a little sigh and then pushes her down again, filling her up, grinding her limp body down against him. “Moaning, writhing, begging for Lily to knot him…”

The next thrust is harder, hilting into her with memories of her father on his mind as Harry squeezes her eyes shut.

It had all gone too far for her to call attention to herself – unable to do anything but hang lip and helpless in his hold.

When he pushes her down on her back she relaxes her face, doing nothing as he crowds between her legs, bending her thighs up and onto his shoulders as he pushed into her, fucking her into the small tent bed, his mouth sealing over one of her nipples with a filthy groan, getting increasingly rough as she didn’t as much as twitch, confident in the alcohol keeping her down and out as he took her for his own pleasure.

He presses a palm against her flat belly almost reverently, feeling the push of the flesh as he thrust into her, buried far beyond reason into her body.

He hilts himself up against her, pushing painfully against her cervix as he comes with a groan and a rush of warm seed, panting as he hoisted her hips up and against himself with a sigh.

Harry’s mind had frozen somewhere at the feeling of the rush of sticky want, at the feel of her godfather filling her up, the sensation foreign and new and so overwhelmingly _wrong_ that she doesn’t know what to do about it.

 _I’m not taking any potions,_ she thinks mutely, unable to comprehend that her godfather had had the audacity to cum inside of her. _I’m not-_

He doesn’t pull out of her, his hands brushing down her skin, tugging at her nipples, tongue flattening against her thigh, the rough stubble prickling against her as he nibbled against the sensitive skin and it doesn’t take long before he was hardening again, swelling inside of her as he slowly pulls out with a little tug to release the head.

He rolls her onto her stomach, straddling the back of her thighs and nudging his cock back up against her folds, finding the entrance and sliding back into her with a sigh, bottoming out with a small smack of his hips against her.

He kneads her rump as he fucks her, working the flesh almost painfully in rough palms as she lies limp beneath him, soon sliding down over her hips and up her back as he flattens himself against her, curving his hips to take her fast and hard while wiggling his hands beneath her, grasping her breasts, just holding them as he thrusts into her.

The feel of him – the heavy weight, the grunts as he pushed into her, the overwhelming feel of being spread on his cock, the push of the cum inside of her with every hilting of his cock-

Harry can feel her orgasm building at the first hint of his knot swelling and dragging against her entrance.

 _He can’t be thinking of knotting me,_ Harry thinks as it swells, pushing up against her entrance with every thrust forward, grunting as his hips smacks against her rump with increasing harshness.  _He can't be-_

But he _was_.

One hand finds and presses down on her neck, the other against her shoulder, leveraging him up, pushing her hard into the bed as he snapped his hips down sharply, forcing the knot past her entrance and into her as he curses and she jerks at the feeling, shocked and biting down hard on the pillow she was buried into to keep from crying out as it swelled painfully inside of her, locking him up tight against her, the head pushed hard against the entrance of her womb as he came inside of her a second time.

Harry feels a mute buzz of shock at the feel of her godfather’s knot, at the feeling of being _bred_ as he filled her up, rocking lazily against her rump as he slowly relaxed, making sure she was taking every last bit of his seed before he curled up against her back, rolling them over to the side in an echo of how he’d taken her at the peak of her heat.

"I love you, James," he whispers against her neck.

Harry lies awake for a long time, staring into the darkness of the tent, her godfather’s cock limp inside of her and the echo of her father's name ringing hollowly inside her mind.

**Author's Note:**

> For someone who isn't overly a fan of reading anything with Sirius I sure like writing him, I realize. 
> 
> This is a bit of a dark play on their relationship but it was interesting to write because of it being so complicated. 
> 
> And, really, you have to admit the title is clever.
> 
> I was deciding between writing this piece and another one with Oliver Wood/Fem!Harry/Angelina Johnson so - that's a project that'll probably appear in the near days. You're always welcome to swing by artsy-death on tumblr if you have pairings or ideas you'd love to see or just want to see what other projects I'm prodding around with.
> 
> It's time for me to walk my dog and eat some lunch before I get to anything else! 
> 
> It's snowing outside after sunshine yesterday so I'm not exactly looking forward to it but, ah. I love him so, just gotta get to it.
> 
> Hope you enjoyed!


End file.
